Check around their vents - if you find any small white clumps at the base of the feathers then they have lice (the clumps are lice eggs).
Easily treated - you'll need to change their bedding/nesting material and dust it with an appropriate powder. Also dust the birds vent area and under their wings with an appropriate treatment (these remedies will be easy to get hold of, most pet shops will stock it for caged birds).
Change bedding regularly & treat each time, and check the birds weekly (to begin with) to give them a healthcheck
Good luck!
Easily treated - you'll need to change their bedding/nesting material and dust it with an appropriate powder. Also dust the birds vent area and under their wings with an appropriate treatment (these remedies will be easy to get hold of, most pet shops will stock it for caged birds).
Change bedding regularly & treat each time, and check the birds weekly (to begin with) to give them a healthcheck
Good luck!